Step into any professional car workshop, and you’ll often notice the tools being used aren’t your usual battery or mains-powered items. They’ll have a long hose connected to an air compressor. The benefits of these kinds of accessories are clear: you’re not tied to a plug socket, or at the mercy of a battery’s charge. The tools deliver consistent power, and with few moving parts, they’re usually extremely robust, compact, light and wieldy – important if they’re being used all day, every day.
But at the heart of all this is the air compressor itself: a large cylinder with some kind of electric, petrol or diesel-fed motor attached. The motor pressurises air in the cylinder. Once you activate a tool, the tank depressurises, causing air to be fed under extremely high pressure into a wide variety of tools. Once the tank starts to run low on air, the compressor turns itself on to feed more air into the system to pressurise – meaning you can carry on with your work. Motorcycle lift
Air compressors are a fairly large investment, and you’ll need to spend more on the tools you need. That means they’re not really aimed at the occasional DIYer, but for the keen car restorer or someone who really enjoys the challenge of keeping their vehicle fleet on the road, they can be a godsend. It’s for that reason we’ve focused on the more affordable end of the market.
READ NEXT: The best super glue
There’s a huge range of tools which can be powered from an air compressor. For automotive applications, that includes blow guns for blasting dirt through pipes and hoses, paint guns, tyre inflators, air ratchets, reciprocating saws, cutting wheels, air chisels, die grinders, and more besides. The beauty is that these tools are often cheaper to buy than the mains-powered equivalents.
READ NEXT: Best wall filler
It really depends on the tools that you’re planning to use. Every air tool will have a requirement for air flow (measured in cubic feet per minute, or CFM) and air pressure (measured in pounds per square inch, or PSI), so you should ensure the compressor you choose exceeds both of those figures. A good rule of thumb is to increase the maximum figures required by the tools by 50% to ensure your compressor has the headroom to operate properly.
READ NEXT: Best paint roller
Air compressors at the DIY end of the market tend to be electric. That means they can be stored easily and used in confined spaces without the ventilation requirements needed by those which use liquid fuel. You’ll find electric air compressors ranging from 5 or 6 CFM right up to 30 CFM or more, which matches the output of many of the punchiest professional petrol and diesel equivalents.
The key difference is that petrol and diesel compressors can be used anywhere and without the need for a nearby electricity supply. That makes them ideal for building sites or remote locations.
Many compressors use oil to lubricate the internal moving parts. But some electric air compressors boast an oil-free pump, which cuts down on your maintenance overheads and ensures the air will be free from minute quantities of oil. Removing the need for oil means there’s a little less you have to think about when using the compressor.
However, there’s nothing wrong with air compressors that have oil lubrication; in fact the majority of compressors on the market use this technology, so opting for oil-free may well cut down your options when you’re searching for a compressor with the specs you need.
READ NEXT: The best paint sprayer
Price: £156 | Buy now from Machine Mart
As an excellent all-rounder for the beginner, the Airmaster really hits the spot. Yet despite its price, its specs are still easily strong enough for many trades, too. A twin outlet with two pressure gauges, plus a regulator, allows you to use multiple tools without the need to be connecting and reconnecting frequently.
Its 7 CFM rating and a maximum working pressure of 116 PSI means it’s ideally suited for most automotive applications, from paint spraying to ratchets and impact wrenches, whilst automatic stop-start means you don’t need to down tools in the middle of a job to fire up the compressor. The oil filler is easily accessible, and there’s a window on the side of the casing to quickly check the oil level. Plus it’s on wheels, making it easy to haul out onto your driveway using the supplied handle.
Key specs – Air tank volume: 24 litres; Air displacement: 7 CFM; Maximum working pressure: 116 PSI; Motor: 2.0hp/1,500W
Buy now from Machine Mart
Price: £78 | Buy now from Machine Mart
For when space is at a premium, or you value total portability, the Clarke Monza is a superb choice. It doesn’t have a tank like the others here, so it can’t deliver quite the same punch, but the gap is less than you’d think. Still, you might find its output limits you to less air-hungry tools, but it’s well suited to blow guns, paint guns and tyre inflators.
The 5.77kg briefcase-sized compressor has storage for its mains cable and three-metre air line, making it as ideal for trips away as it is around the home and garage. The air line itself features a quick release system allowing you to quickly switch between a range of supplied adaptors for inflating sports equipment, bicycle tyres, and balloons, plus the blow head and tyre inflator with pressure gauge. The quick release coupler can be removed to connect other air tools, too.
Key specs – Air tank volume: 0 litres; Air displacement: 6.35 CFM; Maximum working pressure: 115 PSI; Motor: 1.5hp/1,100W
Buy now from Machine Mart
Price: £359 | Buy now from Machine Mart
As you might expect, you’ll pay more for an air compressor with more oomph, but given the Clarke Raider’s mighty 14.5 CFM flow rate, a sub-£360 price tag is still very competitive. Everything about the Clarke is bigger: it has a 50-litre air tank and a 3hp, 2,200-watt motor; it weighs nearly 40kg, too, but fortunately it’s on wheels and can be pulled about using its transport handle.
With that large tank, the Raider is well suited to bigger workshop jobs such as large-scale spraying which requires a constant supply of air. And with that impressive flow rate, it’ll match up well with bigger sandblasters as well as other less-powerful tools. It has two outlets, both with pressure regulators that makes swapping between tools far quicker and easier, and automatic on/off means you won’t need to down tools.
Key specs – Air tank volume: 50 litres; Air displacement: 14.5 CFM; Maximum working pressure: 116 PSI; Motor: 3.0hp/2,200W
Buy now from Machine Mart
Price: £359 | Buy now from Machine Mart
The Clarke Shhh Air really does live up to its name: at 43dB, the noise it emits is comparable to a quiet conversation, making it ideal for spare-room workshops, shops or laboratories. It’s small, too, and has a footprint similar to a piece of A3 paper – the trade-off is its small air tank, which is just 9 litres, and a CFM of just 0.88.
Still, for lighter automotive use, it’s perfectly fit for purpose. It’ll handle light spray gun duties, stapling for car upholstery, powering a blow gun and tyre inflation. It’s not on wheels, but weighing in at less than 20kg, it doesn’t need to be. The single outlet has a pressure gauge, and it’s easy to top up and check the oil. For light use that won’t upset the neighbours if you’re working late into the evening, the Clarke Shhh Air is a great choice.
Key specs – Air tank volume: 9 litres; Air displacement: 0.88 CFM; Maximum working pressure: 116 PSI; Motor: 0.3hp/190W
Air Gauge Tire Pressure Copyright © MVF Global 2023. All rights reserved. Expert Reviews™ is a registered trade mark.